In our country farmers have to face many difficulties because of the poor irrigation system. During flood situation, excessive waters will be staged in paddy field producing great loss and pain to farmers. So, proper Irrigation mechanism is an essential component of paddy production. Poor irrigation methods and crop management are rapidly depleting the country’s water table. Most small hold farmers cannot afford new wells or lawns and they are looking for alternative methods to reduce their water consumption. So proper irrigation mechanism not only leads to high crop production but also pave a way for water saving techniques. Automation of irrigation system has the potential to provide maximum water usage efficiency by monitoring soil moistures. The control unit based on Artificial Neural Network is the pivotal block of entire irrigation system. Using this control unit certain factors like temperature, kind of the soil and crops, air humidity, radiation in the ground were estimated and this will help to control the flow of water to acquire optimized results. / Water is an essential resource in the earth. It is also essential for irrigation, so irrigation technique is essential for agriculture. To irrigate large area of lands is a tedious process. In our country farmers are not following proper irrigation techniques. Currently, most of the irrigation scheduling systems and their corresponding automated tools are in fixed rate. Variable rate irrigation is very essential not only for the improvement of irrigation system but also to save water resource for future purpose. Most of the irrigation controllers are ON/OFF Model. These controllers cannot give optimal results for varying time delays and system parameters. Artificial Neural Network (ANN) based intelligent control system is used for effective irrigation scheduling in paddy fields. The input parameters like air, temperature, soil moisture, radiations and humidity are modeled. Using appropriate method, ecological conditions, Evapotranspiration, various growing stages of crops are considered and based on that the amount of water required for irrigation is estimated. Using this existing ANN based intelligent control system, the water saving procedure in paddy field can be achieved. This model will lead to avoid flood in paddy field during the rainy seasons and save that water for future purposes.

Resumo: A cafeicultura irrigada vem crescendo nos últimos anos no Brasil devido aos bons resultados apresentados em várias regiões do país, porém um dos grandes problemas de se utilizar a irrigação na cultura do café tem sido o manejo, pois são poucas as informações em relação a esse assunto. Objetivou-se com este trabalho avaliar o desenvolvimento vegetativo e as características fisiológicas do cafeeiro irrigado com diferentes lâminas de água, calculadas em função da evaporação de água do Tanque Classe A, durante as fases de expansão e granação dos frutos que são as, mas críticas da cultura em relação ao déficit hídrico. O experimento foi conduzido no período de novembro de 2011 até março de 2012, na Fazenda Nova América situada no município de Botucatu-SP, localizada nas coordenadas geográficas 22°56' S e 48°21'W, altitude de 663m, em um cafezal da cultivar Obatã IAC 1669-20 com oito anos de idade. O experimento foi composto por seis tratamentos onde T1 foi a testemunha sem irrigação, as demais lâminas de água aplicadas foram correspondentes a 60% (T2), 80% (T3), 100% (T4), 120% (T5), 140% (T6) da evapotranspiração da cultura (Etc) calculada conforme a evaporação de água do Tanque Classe A. O crescimento de ramos e números de par de folhas, foram superiores nos tratamentos T5 e T6. O número de entrenós do T5 foi superior em relação aos demais tratamentos. As variáveis correspondentes à condutância estomática (gs) e temperatura foliar (Tf) não apresentaram diferenciação entre os tratamentos. Porém, os valores médios da assimilação líquida de carbono (A) dos tratamentos irrigados, apresentaram valores maiores em relação à testemunha sem irrigação / Abstract: The purpose of the work was to evaluate vegetative development and physiological characteristics cultivated under different water depths, calculated according to the class A pan evaporation, the phases of expansion and grain formation that are overpriced, but criticism of culture in relation to water deficit. The experiment was conducted from November 2011 until March 2012, on the farm New America, in the municipality of Botucatu - SP, located by geographic coordinates 22 ° 56 'S and 48 ° 21' W, altitude of 663m, in a coffee plantation Obatã IAC 1669-20 cultivar with eight years of age. The experiment consisted of six treatments where T1 was no irrigation, other water depths were applied at 60% (T2), 80% (T3), 100% (T4), 120% (T5), 140% (T6) of crop evapotranspiration (Etc) calculated according the evaporation of water from the class A pan. The growing numbers of branches and leaf pair, were higher in treatments T5 and T6. The number of internodes of T5 was high to other treatments. The variables corresponding to stomatal conductance (gs) and leaf temperature (Tf) showed no difference between treatments. However, the mean values of net carbon assimilation (A) of irrigated treatments showed higher values compared to no irrigation / Orientador: Raimundo Leite Cruz / Coorientador: Rogério Peres Soratto / Banca: Antonio de Pádua Sousa / Banca: Raimundo Leite Cruz / Banca: Leandro Lemos Borges / Mestre

Water is Australia's most precious natural resource. The quality, quantity and availability of this resource is the single factor most limiting agricultural development and sustainability in this country. Since the development of Australia's cotton industry in the 1960's, and the expanding areas of irrigated crop, there has been an increasing demand placed on the limited water resources of the country. Consequently, the cotton industry has been the target of protest from conservation groups, residents of rural townships and others farmers engaged in competing rural sectors. Therefore, cotton farmers need to develop best practice in terms of water use efficiency. Not only does this make good ecological sense but also good economic sense. Traditional methods of irrigation scheduling have proven to be subjective and haphazard. Recently developed methods, while providing more quantitative techniques, do not give a synoptic view of a field's or region's crop moisture status. The main objective of this project was to evaluate an airborne thermal scanner (8-12 µm) as practical tool for monitoring the water requirements of an irrigated cotton crop. The thermal scanner was mounted below a light aircraft and imagery was collected over Field 86 , Togo Station, north-west NSW during the summer of 1990/91. The field was divided into nine treatments for the purpose of this project. Three irrigation regimes (early, normal and late) with three repetitions were applied to the nine treatments. A total of fourteen images were selected for analysis. These images were grouped into sets of AM images, PM images as well as diurnal groupings which were interpreted for three separate dates during the growing season. Ground based measurements of infrared crop surface and soil temperature, soil moisture deficit, leaf area index (LAI) and the Crop Water Stress Index (CWSI) were collected to calibrate the airborne imagery. Imagery was in the first instance visually interpreted to determine what information could be gained from this technique. Patterns on the imagery were related to diurnal variations in soil and crop temperatures. This investigation revealed a number of soil related phenomena inherent to the field which were influencing the airborne detected temperatures. While this technique showed variability across the field, the interpretation was somewhat subjective. Temperature values were extracted from the imagery in order to conduct an analysis of variance (ANOVA) between the airborne and ground measurements of infrared crop surface temperature. In summary, this analysis did not show a strong relationship between the airborne and ground based measurements. A number of contributing factors have been proposed as the reason for this variation in the two datasets. Pearson's correlation analysis was applied to the AM (r = 0.65) and PM (r = 0.32) groups of airborne and ground temperatures. Airborne derived calculations of the CWSI were compared to ground based measurements for the AM group of flights. These derived values were only acceptable in instances where the ANOVA results had shown them to approximate the ground based measurements. While airborne thermal imagery provides a useful tool for determining general variations in temperatures across a field, there are many additional factors, the most dominant being the thermal characteristics of the background soil, which influence the detected temperatures. This technique does not provide the precise quantitative information required to accurately determine across-field measurement of the CWSI.

Several methods of infering plant water stress for irrigation scheduling are based upon measurements of the environment in which the plants grow. These measurements include parameters such as soil water content, air temperature, pan evaporation and incident radiation. It is hypothesized that improved estimates of plant water deficit can be obtained by direct measurements made on the plants. The main objective of this study was to test the performance of measurements of canopy temperature and leaf water potential for irrigation scheduling. This study seeks to establish whether a correlation exists between these monitoring methods and measurements of soil moisture content, leaf area, and evapotranspiration. The experiments were conducted in first-year peppermint irrigated at five different rates. Canopy and air temperatures were measured with a hand-held infrared thermometer. Leaf water potential was measured with a pressure bomb. A non-stressed baseline for the difference between canopy temperature and air temperature using data from well-watered plants was used together with the vapor pressure deficit to determine the crop water stress index (CWSI). The results of this study show that the CWSI is well correlated to evapotranspiration deficit and is useful for irrigation scheduling. The relationship between leaf area yield and CWSI in peppermint was described by a quadratic function. Leaf water potential varied during the day in such a way that it was not possible to establish a relationship with water stress, differences in soil moisture content, or different irrigation levels. Leaf water potential was influenced by the daily weather conditions and represented the current demand more than the cumulative demand. The results of this study indicate that mid-day pressure bomb measurements cannot be used in irrigation scheduling. Predawn measurements of leaf water potential were stable, were well correlated with the different irrigation levels and soil moisture content, and therefore may be useful in irrigation scheduling. / Graduation date: 1993

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 61-63). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 61-63). Also available on the Internet.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

Revised; Originally published: 2009 / 6 pp. / Proper irrigation management requires that growers assess their irrigation needs by taking measurements of various physical parameters. Some use sophisticated equipment while others use tried and true common sense approaches. Whichever method used, each has merits and limitations. In developing any irrigation management strategy, two questions are common: “When do I irrigate?” and “How much do I apply?” This bulletin deals with the WHEN.

Limited water supplies are available to satisfy the increasing demands of crop production. It is therefore very important to conserve the water, which comes as rainfall, and water, which is used in irrigation. A proper irrigation water management system requires accurate, simple, automated, non-destructive method to schedule irrigations. Utilization of infrared thermometry to assess plant water stress provides a rapid, nondestructive, reliable estimate of plant water status which would be amenable to larger scale applications and would over-reach some of the sampling problems associated with point measurements. Several indices have been developed to time irrigation. The most useful is the crop water stress index (CWSI), which normalizes canopy to aIr temperature differential measurements, to atmospheric water vapour pressure deficit. A field experiment was conducted at Cedara, KwaZulu-Natal, South Africa, to determine the non-water-stressed baselines, and CWSI of cereal rye (Secale cereale L.) from 22 July to 26 September 2002, and aImual (Italian) ryegrass (Lolium multiflorum Lam.) from October 8 to December 4, 2002, when the crops completely covered the soil. An accurate measurement of canopy to air temperature differential is crucial for the determination of CWSI using the empirical (Idso et al., 1981) and theoretical (Jackson et al., 1981) methods. Calibrations of infrared thermometers, a Vaisala CS500 air temperature and relative humidity sensor and thermocouples were performed, and the reliability of the measured weather data were analysed. The Everest and Apogee infrared thermometers require correction for temperatures less than 15 QC and greater than 35 QC. Although the calibration relationships were highly linearly significant the slopes and intercepts should be corrected for greater accuracy. Since the slopes of the thermocouples and Vaisala CS500 air temperature sensor were statistically different from 1, multipliers were used to correct the readings. The relative humidity sensor needs to be calibrated for RH values less than 25 % and greater than 75 %. The integrity of weather data showed that solar irradiance, net irradiance, wind speed and vapour pressure deficit were measured accurately. Calculated soil heat flux was underestimated and the calculated surface temperature was underestimated for most of the experimental period compared to measured canopy temperature. The CWSI was determined using the empirical and theoretical methods. An investigation was made to determine if the CWSI could be used to schedule irrigation in cereal rye and annual rye grass to prevent water stress. Both the empirical and theoretical methods require an estimate or measurement of the canopy to air temperature differential, the non-waterstressed baseline, and the non-transpiring canopy to air temperature differential. The upper (stressed) and lower (non- stressed) baselines were calculated to quantify and monitor crop water stress for cereal rye and annual ryegrass. The non-water-stressed baselines were described by the linear equations Te - Ta = 2.0404 - 2.0424 * VPD for cereal rye and Te - Ta = 2.7377 - 1.2524 * VP D for annual ryegrass. The theoretical CWSI was greater than the empirical CWSI for most of the experimental days for both cereal rye and annual ryegrass. Variability of empirical (CWSI)E and theoretical (CWSI)T values followed soil water content as would be expected. The CWSI values responded predictably to rainfall and irrigation. CWSI values of 0.24 for cereal rye and 0.29 for annual ryegrass were found from this study, which can be used for timing irrigations to alleviate water stress and avoid excess irrigation water. The non-water-stressed baseline can also be used alone if the aim of the irrigator is to obtain maximum yields. However the non-water-stressed baseline determined using the empirical method cannot be applied to another location and is only valid for clear sky conditions. And the non-water-stressed baseline determined using theoretical method requires computation of aerodynamic resistance and canopy resistances, as the knowledge of canopy resistance, however the values it can assume throughout the day is still scarce. The baseline was then determined using a new method by Alves and Pereira (2000), which overcomes these problems. This method evaluated the infrared surface temperature as a wet bulb temperature for cereal rye and annual ryegrass. From this study, it is concluded that the infrared surface temperature of fully irrigated cereal rye and annual ryegrass can be regarded as a surface wet bulb temperature. The value of infrared surface temperature can be computed from measured or estimated values of net irradiance, aerodynamic resistance and air temperature. The non-water-stressed baseline is a useful concept that can effectively guide the irrigator to obtain maximum yields and to schedule irrigation. Surface temperature can be used to monitor the crop water status at any time of the day even on cloudy days, which may greatly ease the task of the irrigator. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003